Blend together sugar, margarine, cream cheese, salt, almond extract, vanilla, and egg yolk with mixer. Mix in flour until well blended.
Roll into a ball and wrap in plastic wrap.
Refrigerate for two hours.
Heat oven to 375 degrees. Roll out dough, one third at a time, on a lightly floured surface. Using a cookie cutter dipped in flour, cut out cookies as close together as possible.
Place the cookies one inch apart on ungreased cookie sheets. To prevent breaking, move cookies to and from baking sheets with a wide spatula or pancake turner.
Leave cookies plain or, if desired, brush with slightly beaten egg white and spring with colored sugar.
Bake for 7 to 10 minutes or until bottoms of cookies are a light golden brown. Cool completely.
{My mom always told me the most important part of making sugar cookies was to take them out as soon as they were even slightly brown on the bottom, or not at all. I took mine out before they had even browned and left them on the cookie sheet to cool. That made them extra soft and delicious.}
If desired, use the almond glaze below.